--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bn_mp_neg.c	Mon May 31 18:25:22 2004 +0000
@@ -0,0 +1,28 @@
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, [email protected], http://math.libtomcrypt.org
+ */
+#include <tommath.h>
+
+/* b = -a */
+int mp_neg (mp_int * a, mp_int * b)
+{
+  int     res;
+  if ((res = mp_copy (a, b)) != MP_OKAY) {
+    return res;
+  }
+  if (mp_iszero(b) != MP_YES) {
+     b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS;
+  }
+  return MP_OKAY;
+}